ferr-

Ferr- is a combining form used like a prefix meaning “iron.” Ferr- is occasionally used in scientific terms, especially in chemistry.

Ferr- comes from Latin ferrum, meaning “iron.” The Greek equivalent was sídēros, “iron,” which is the source of the combining form sider–, as in siderite.

What are variants of ferr-?

Ferr- is a variant of both ferro- and ferri-, which lose their -o- or -i- when combined with words or word elements beginning with vowels. Want to know more? Read our Words That Use articles for ferro- and ferri-.

One example of a scientific term that features the form ferr- is ferrite, “a compound, as NaFeO₂, formed when ferric oxide is combined with a more basic metallic oxide.” Essentially, ferrite is a kind of hard substance that contains iron.

The ferr- part of the word means “iron.” The suffix -ite has various meanings, including as a way to name minerals and fossils. Ferrite literally means “iron mineral.”

What are some words that use the combining form ferr-?

• ferrate
• ferredoxin
• ferreous
• ferrous

What are some other forms that ferr– may be commonly confused with?

• facio-
• fascio-

Not every word that begins with the exact letters ferr-, such as ferry or ferret, is necessarily using the combining form ferr- to denote “iron.” Learn where ferret comes from at our entry for the word.

The suffix -ous means “possessing, full of.” With this in mind, what is an everyday definition of the word ferrous?